LL-37 reverse sequence is a 37-amino-acid synthetic peptide in which the residue order of human LL-37 is reversed from C-to-N sequence order while the peptide itself is synthesized conventionally in the N-to-C direction.
Because the peptide contains the same amino-acid composition as native LL-37, it retains the same molecular formula and calculated molecular weight while presenting a fundamentally different primary-sequence order.
This makes AS2701 useful as a comparator in LL-37 structure–function studies where researchers want to examine the contribution of sequence directionality independently from overall amino-acid composition.
Product Information
| Property | Specification |
|---|---|
| Product Name | LL-37, Reverse Sequence |
| Catalog No. | AS2701 |
| Sequence | SETRPVLNRLFDKIRQVIRKFEKGIKEKSKRFFDGLL |
| Length | 37 amino acids |
| Molecular Formula | C₂₀₅H₃₄₀N₆₀O₅₃ |
| Molecular Weight | 4493.37 Da |
| Peptide Type | Reverse-sequence LL-37 analog |
| Parent Peptide | Human LL-37 |
| Amino-Acid Composition | Identical to native LL-37 |
| Form | Lyophilized peptide |
| Available Purity | Crude to 98% |
Reverse Sequence versus Native LL-37
The sequence of native LL-37 is:
LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES
The AS2701 sequence is:
SETRPVLNRLFDKIRQVIRKFEKGIKEKSKRFFDGLL
The amino-acid inventory is therefore unchanged, but its positional organization is reversed.
This distinction can influence amphipathicity, secondary-structure preference, aggregation, membrane orientation, and molecular recognition. AS2701 is consequently more informative as a sequence-orientation comparator than as a generic unrelated negative-control peptide.
For direct comparison, see LL-37, Antimicrobial Peptide, Human (AS2699).
Appropriate Use as a Control Peptide
A reverse-sequence peptide can help test whether an experimental phenotype depends on the native order of amino acids rather than simply overall composition or bulk physicochemical properties.
However, reverse sequence should not automatically be interpreted as biologically inactive.
Because charge, elemental composition, and total hydrophobic residue content are retained, AS2701 may still interact with membranes or other experimental components depending on the assay. Its behavior should therefore be experimentally characterized for the specific system in which it is being used.
Reverse versus Scrambled Controls
A reverse peptide and a scrambled peptide answer different experimental questions.
A reverse sequence changes residue direction while retaining a mathematically defined relationship to the native sequence. A scrambled control redistributes residues into a different non-native order.
For mechanistic studies, choosing between reverse, scrambled, truncated, alanine-substituted, or charge-modified controls should depend on the variable the experiment is intended to isolate.
Researchers requiring additional LL-37 controls or custom sequence variants can use our Custom Peptide Synthesis service.
Experimental and Procurement Considerations
When native LL-37 and AS2701 are compared, matching purity, counterion, concentration determination, solvent, and storage history can reduce variables unrelated to sequence order.
Because both peptides have the same molecular formula and calculated molecular weight, mass alone cannot distinguish the native and reverse sequences. Sequence assignment and chromatographic behavior therefore become particularly relevant when comparing these materials.
This makes batch traceability and clear catalog identification especially useful for laboratories maintaining parallel LL-37 control sets.
Storage and Handling
Store the lyophilized peptide according to the batch-specific specification. In comparative studies, prepare native and reverse LL-37 using equivalent handling conditions wherever possible.
Research Use Only
LL-37, reverse sequence is supplied for research use only. It is not intended for therapeutic, or human use.